The rivalry continues between AT&T and T-Mobile as the two carriers adjust prices once again, but you may be surprised at who is raising prices and who is cutting them.

According to AT&T, it is cutting the price of its 2GB shared data plan by $15 per month. That means that users will pay $80 per month for one line with a two-year contract, and only $40 per month for each additional smartphone instead of $55.

Customers who bring their own phones or purchase them through AT&T will pay $65 a month for one line, which is a cut from $80 per month. Those with two lines will pay $90 per month, down from the previous $105 per month.

AT&T is likely looking to lure customers from their older plans to the newer shared data plans, which include unlimited talk and text with mobile hotspot use at no extra charge.

T-Mobile, on the other hand, is replacing an unlimited plan and raising prices at the end of March by $10. More specifically, the $70 per month unlimited data plan is being booted for a 5GB offering instead, which is still set at $70.

[SOURCE: rizzif]

For unlimited, customers will have to pay $80 per month.

But on the brightside, T-Mobile is bumping up its $50 per month plan from 500MB to 1GB, and the $60 per month plan from 2.5GB to 3GB. Customers can also look forward to unlimited texting from the U.S. to over 120 countries.

It's suprising that T-Mobile is raising its unlimited plan price, since cheap unlimited plans are a key differentiator in a market where the top guys (Verizon and AT&T) have done away with such plans for tiered options. But at the same time, T-Mobile said that these plans are getting expensive, and it needs to be able to afford to build its network.

T-Mobile added that data demand has been rising under its existing plans, and that subscribers use nearly 50 percent more data now than they did a year ago.

In fact, monthly usage on unlimited plans has nearly doubled and tops the 5GB mark.